Do ND filters alter the aperture when using the anamorphic?

[Kuock]

Hi everybody

I've read Barry's book and I keep in mind the minimum aperture chart when shooting with the anamorphic adapter but there is something I doubt (stupid thing I'm afraid)

When setting a ND filter the light decreases and so we must to open up the iris.

My question is do we have to set the same minimum aperture (the one in the chart) when putting a ND filter as when no putting it? (the F stops will vary because there are less light only)

Thank you for your replies

 

[Barry_Green]

Yes, the aperture is what's important. The ND filter cuts the amount of light coming in, but you still have to have the right aperture for the depth of field to be deep enough to overcome the astigmatism. So the answer is: you need to set the right aperture. Use the ND filter as an additional exposure control, but make sure the aperture is set deep enough (according to the charts).

 

[khmuse]

The presence or absence of either the in camera or external neutral density filter(s) will not change the necessity of using the correct aperture for a given focus and zoom setting when using the anamorphic adapter. It is the relative focal shift of the adapter in the horizontal and vertical planes that require stopping down the camera to get both within the depth of field for a given setup. Neutral density is simply a broad band (not spectrally specific) filter which has no appreciable effect on the focal characteristics. It only reduces the total light reaching the camera's CCDs without having any other (intentional) effect.

Continue to use the charts recommendations with or without any ND filtration; there is no difference in the requirements for the camera's aperture setting.